Archive for the 'Neuroscience' Category

Living in a complex society means that some decisions are made for us. In a representative democracy, this means our elected officials, at every level, can have incredible power over our lives. The social contract, however, is that these elected officials should know what they are doing, act in the public interest, listen to their constituents, and engage in due diligence based on valid evidence-based processes. Well, that’s the ideal, and it’s pretty clear that we generally fall far short.

One limitation is that people are flawed and have complex motivations and often fall prey to ideology. However, there is also a collective problem of political will, with often perverse incentives baked into the system itself.

These inherent flaws in the system become increasingly frustrating as there are obviously better ways to do things, and yet we can’t seem to get out of our own way. On the bright side it is possible to slowly build the political will in response to a growing body of evidence. Scientific evidence on the risks of second-hand smoke, for example, supported the political will to ban smoking in many public locations, which has led to an improvement in health.

But there are other areas where the science is increasingly clear, the arguments seem one-sided, and yet we seem to be stuck in paralysis. Changing from Daylight Savings time to Standard time is hazardous. It is linked to worse sleep, more accidents, and even more heart attacks. There is also no good reason for the change. It’s just dumb. It seems that we are long past the time of having enough evidence, arguments, and political will to just ditch the change – so what’s the holdup?

There has been a very interesting debate going on in neuroscience over the impact of so-called “brain training” activities and cognitive ability and decline. No one study, of course, is ever going to be the final word on this debate, but a new study does add one more piece to the puzzle. Unfortunately it shows that increased mental engagement (doing puzzles, engaging in problem solving, etc.) does not alter the course of mental decline in later years.

But let’s back up and frame the question a bit more. The overarching question is – what is the effect on the brain and on cognitive ability from engaging in various kinds of mental activity? A cottage industry has risen out of one extreme end of opinion on this question, the notion that certain kinds of mental activity could have wide ranging benefits. This is the “brain training” claim – doing specially designed puzzles will make you smarter, and maybe even prevent dementia.

Although Lumosity often gets cited for making these claims, I think it started much earlier, in the 1990’s with the Baby Mozart movement. In 1993 a short paper was published in Nature, involving a small number of college students who were either exposed to classical music or just relaxation. They were then tested with a paper folding task, and those who listened to the music did a litter better. This was a small preliminary study in college students showing a very narrow effect. Yet somehow this tiny and insignificant paper was used to create the myth of the so-called “Mozart effect” – that children who are exposed to classical music will become generally smarter.

Later studies showed no such effect, but the genie was out of the bottle. A cottage industry of “Baby Mozart” and “Baby Einstein” (because, why not?) products still thrive to this day. This spawned a more general claim that mental activity can “train your brain” to make you generally smarter.

Have you ever been in a semi-familiar location but couldn’t quite place where you were, then suddenly the landmarks line up and you know where you are? This might happen when entering a familiar location from an unusual direction, for example. Also (a seemingly unrelated question), when you visualize abstract ideas, do you arrange them physically. For example, do you visualize time (like days, weeks, months, years), and if so is there a particular physical relationship by which you mentally organize the progress of time?

Scientists from the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) and the Kavli Institute for Systems Neuroscience in Trondheim, Norway have published a paper in which they propose these two mental phenomena are directly related. One of the scientists, Edvard I. Moser, won the 2014 Nobel Prize for some of this work.

For background, researchers discovered that there are a type of neuron called place cells in the hippocampus (specifically area CA1) that store the memory for specific locations. When you are in a familiar location, a unique pattern of place cells will light up. Further, there is a second type of cell called grid neurons, which are arranged in a hexagonal pattern in the nearby entorhinal cortex. These grid cells light up in sequence as you move through your physical space – the physical arrangement of the grid neurons map to the physical arrangement of your environment.

This is an elegant system – your brain basically has a movable grid map, the grid keeps track of your local navigation, while the place cells keep track of where the map is.

Is putting your toddler in front of an educational video harmful or helpful? This is an important question for many parents, especially in homes where both parents work and taking care of young children can be hectic. Putting a child in front of a video is the closest things parents have to an off switch for their kids, so it can be very tempting to rely upon the distraction of an iPad or TV to keep their attention while you make dinner or attend to some other task.

There is also a cottage industry of videos marketed to parents with very young children. Some are clearly nothing more than an entertaining distraction, like videos of other children playing with toys (which are incredibly popular). But parents can also be sold on the idea that their children are learning while being distracted, thereby alleviating any guilt from relying on the video-nanny.

There has therefore been increasing research into the effectiveness of video learning for very young children (and older children and adults, but we’ll focus on young children for now). Here is a recent study of this topic which includes a great overview of prior research.

Previous research has mostly shown that young children do not respond to video the same way they respond to a live person. Exposing toddlers to their native language or a foreign language through a video or just audio seems to have no benefit, compared to the identical content presented through a live person. The probable reason for this is that we are programmed from birth to be extremely social, and young children typically will pay great attention to other people – more than anything else. A video of a person, unfortunately, just doesn’t cut it.

How people make ethical decisions is a very interesting line of psychological research. Perhaps the most well-known study is the famous trolley experiment. It is a theoretical question, if you are at the controls of a switch that can change tracks, and a trolley is out of control and heading toward five people that it will surely kill, would you switch the trolley onto another track that only has one person on it? Most people say that they will – they will sacrifice that one person in order to save five.

However, if you are standing next to the track and a very large person is in front of you, would you push them onto the tracks in order to stop the train and save five people (just go with the premise for the sake of the ethical conundrum). Most people will say no. In scenario 1 they will sacrifice one person to save five, in scenario 2 they will not. Why?

Conventional wisdom is that people are more willing to passively allow someone to die rather than actively kill them. The outcome matters less than the mechanism – emotionally, at least.

The deeper issue here, beyond this one ethical calculation, is how we make ethical calculations generally. This mainly comes down to conflict resolution – when competing motivations are moving us toward different behaviors, how do we resolve the conflict? We make such ethical decisions on two levels, intuitive and analytical (the two basic modes of thought that have been elucidated in other contexts as well).

Humans tend to be superstitious creatures, meaning that we sometimes believe in magical causation – if I wear my lucky sweater my favorite team will win. Psychologists have been examining this strange phenomenon for decades, with some interesting results.

A recent study ads one more piece of information to the emerging picture of what drives superstitious beliefs and behaviors, but let’s first give some background.

Superstitious beliefs are primarily about the illusion of control – the feeling that we have some direct or indirect control over the outcome of processes over which we objectively have zero control. Gambling is a common everyday example – gamblers tend to develop all sorts of behaviors they believe will give them a better chance of winning at games which are random. Psychologists divide the notion of control into primary and secondary. Primary control is direct control – if I throw the dice with my left hand I will get a better result. Secondary control is an attempt to harness or align with an outside force, such as luck.

It is always difficult to tease apart the complex causes of human decision-making and behavior, and studies necessarily rely on artificial situations or markers of the behavior in question. But a few fairly clear signals have emerged from the research.

Human brains are perhaps the most complex known structures in the universe (known to us), and while we have discovered a tremendous amount of information about them, there is still much to discover. Recently neuroscientists have discovered a new neuron (brain cell) type, so far discovered only in humans – the rosehip neuron.

Neurons are highly specialized cells in the brain and other parts of the nervous system. They have a general structure that includes a soma, which is the cell body, and projections called dendrites and axons. Generally dendrites are short and numerous and receive electrochemical signals from other neurons. Axons tend to be long and few (often only one) and carry signals away from the soma to other cells. Neurons are therefore a basic component of the nervous system circuit.

Neurons also tend to be either excitatory (increasing the firing of the neuron they synapse on) or inhibitory (decreasing the firing of the neuron they synapse on). Different neuron types are identified by their general shape and their neurochemistry – are they excitatory or inhibitory and what neurotransmitter do they use. The most common neuron type in the cortex is the pyramidal cell, which has a pyramid-shaped soma, a dense bush of dendrites, and one long axon. Pyramidal cells are excitatory and tend to use glutamate as their neurotransmitter.

I understand the need to make headlines eye-catching, but you can do that without misrepresenting the science. The body of the article itself, while it does a decent job of explaining teleology, also misrepresents the implications of the study in a typical way – it fails to put it into the context of existing research.

Mainstream science reporting often follows a typical narrative – we essentially knew nothing, then scientists made this breakthrough discovery, and now we fully understand “the” cause of whatever.

The real scientific narrative is often quite different – we know something about this complex phenomenon, but there is still much that is not known, and now scientists have added one more piece to the puzzle. This is actually, in my opinion, a far more compelling narrative, but you have to tell the whole story of the scientific question, not just the one study.

I am not talking about dubious research, but rather research into the phenomenon of bullshit (BS) itself. BS has an operational definition or paradigm within psychological research – it is the extent to which subject rate as highly meaningful statements which are crafted to be vacuous, unconcerned about the truth, and lacking in any unambiguous meaning. Think just about anything Deepak Chopra says. Such statements are also called “pseudoprofound” when they are BS and try to sound profound or philosophical.

“Intuition expresses visible choices.”

“Meditation makes the entire nervous system go into a field of coherence.”

A recent study extends the research on BS a bit, but first gives a brief summary of what existing research has found:

Recently, some psychological research has focused on individual differences in the extent to which people perceive bullshit as meaningful. These studies have shown that people who rate bullshit sentences as highly meaningful have more religious and supernatural beliefs, are less reflective, intelligent, and numerate, more prone to ontological confusions and conspiratorial ideation, endorse free market policies more, and have more favorable views of Republican presidential candidates in US politics. The aim of this study is to develop the academic field of bullshit further.

Given the relatively few number of references in the paper, it’s probably best to consider these conclusions preliminary. While many of these features make sense, like being prone to believing in the paranormal and conspiracies, I would want to see some independent replication before making any firm conclusion.

There is no question that people occasionally have strange experiences, sometimes very strange. There is a tendency to interpret such experiences as external, reflecting something happening in the world, rather than internal, reflecting something happening in our brains.

Neuroscience, however, has provided us a powerful tool for understanding some of these experiences. They are a window into how our brains construct our experience of reality, and what we experience when that process breaks down or is altered by drugs, trauma, electrical stimulation, oxygen deprivation, or other stressors.

A recent study looking at the hallucinogen DMT (N,N-Dimethyltryptamine) adds an interesting insight into our collective knowledge of these altered states of consciousness. The researchers studied 13 healthy volunteers, who were given placebo, and then in a separate session a week later DMT, and extensively questioned about their experiences. The researchers specifically wanted to test the possibility that a DMT-induced hallucination would be similar to reported near-death experiences.

In short they found that the DMT experiences were extremely similar to near-death experiences (NDE), but let’s look at the details.

They gave the subjects an established NDE scale, which assesses for 16 features reported by those who experience an NDE. A score of 7 or higher is considered to be a genuine NDE. All 13 subjects scored 7 or higher on this scale when given DMT. Ten of the 16 features were statistically more likely during DMT than placebo. And the total scores were similar to a historical control group of reported NDEs. So again – DMT produced an experience that was very similar to reported NDEs.